Hybrid Single Shot Manufacturing of Multi-Materials Structure for Automotive Applications

Multi-material design is one of the most attractive methods for automakers to reduce production cost while achieving lightweighting to meet stringent regulations and fuel efficiency concerns. Lightweighting, parts consolidation, reduction in assembly time and cost, and diverse functionalities are some advantages to the use of multi-material design in the automotive industry. However, the current technology of multi-material manufacturing faces some drawbacks, such as high cycle time, the necessity of various tooling and machinery systems, tight tolerance requirements, and extended planning effort on the production line. In this study, a technique named the Hybrid Single Shot (HSS), which is similar to Polymer Injection Forming (PIF), is used to manufacture CF/Epoxy-Thermoplastic components in a single operation. Unlike the PIF method, a carbon fiber /epoxy prepreg sheet is used as an insert material instead of sheet metal. In this technique, an injected polymer melt behaves like a forming medium to form the inserted thermoset sheet, in a single operation. Molten polymer not only forms but also bonds with the thermoset sheet using the high temperature of the polymer, in one process. CF/Epoxy sheet with injected thermoplastic is a hybrid structure that combines high mechanical properties of thermoset composite with the toughness and complex geometries of injected thermoplastic into a single component. A feasibility study was conducted for developing an integrated technology for the manufacturing of thermoset CF/Epoxy prepreg sheet with an injection of polypropylene to overcome the high cycle time and production cost associated with the manufacturing of such hybrids. Several sample parts were manufactured to demonstrate the effect of the process parameters on the process performance and the appearance of the final hybrid component. Although the results were promising, it showed some practical challenges such as excessive penetration, inadequate deformation, and warpage. Various process and design parameters are applied to the hybrid single shot process to circumvent these challenges. For example, a lower injection speed rate and the injection temperature are applied to increase the viscosity to prevent the penetration of polymeric melt through the thermoset sheet. Also, to evaluate the impact of polymer injection on the degree of cure of the prepreg sheet, Differential Scanning Calorimetry (DSC) analysis is conducted at a different pre-heat time before and after injection. The results showed that an increase in pre-heating time and injection temperature significantly enhanced the curing of the prepreg sheet after injection. Further, the mechanical properties of the hybrid part will be examined to identify the effect of individual properties of CF/ Epoxy and PP on the final component. Another contribution of this study is that it avoids many difficulties that conventional TS/TP joining techniques face. Specifically, these traditional joining methods, namely mechanical fastening, adhesive bonding, and welding, are time-consuming and labor-intensive. Also, mechanical fastening causes delamination and possible galvanic corrosion while adhesive bonding requires extensive surface preparation. Despite the time and weight advantages, welding techniques tend to create local delamination due to high local temperature. The hybrid single shot method is a promising alternative to overcome all the challenges that conventional methods face. A lap shear test is conducted to address the bonding conditions between polypropylene and CF/Epoxy prepreg. The experimental results presented in the previous chapters have revealed that the final geometry of the hybrid part is highly dependent on the preheating conditions and pressure field applied on the prepreg sheet during the injection phase. The pressure distribution is then a function of selected polymer, process settings, and most importantly of the geometry of the flow channel. To model the forming of the prepreg sheet due to this non-uniform pressure field, it is essential to couple all the physical events occurring inside the cavity. Therefore, the last contribution of this study is to have a better understanding on the effect of interaction injection, forming and curing on the final geometry of prepreg sheet, a quick yet accurate simulation of the HSS process. This simulation includes the consideration of the non-uniform pressure distribution of the melt flow and the prepreg sheet deformation behavior based on a new experimentally calibrated numerical approach

Investigation the effects of cutting parameters on power consumption in turning of haynes 242 nickel-based super alloy by RSM and GA

Talaşlı imalatta yaygın kullanımı nedeniyle tornalama işleminde güç tüketimini azaltmak sürdürülebilir bir üretim süreci için kilit faktörlerden biridir. Nikel bazlı süper alaşımlar, üstün mekanik özelliklerinden nedeniyle endüstride sıklıkla tercih edilirler. Bu çalışmanın amacı işlem parametrelerinin Haynes 242 nikel bazlı süper alaşım malzemenin tornalanmasında güç tüketimi üzerine etkilerinin incelenmesidir. Bu kapsamda, yanıt yüzeyi yöntemi (Response Surface Method-RSM) ile birleştirilen üç seviye Box-Behnken tasarımı ve genetik algoritma (GA) uygulanarak minimum güç tüketiminin tahmin edilmesinde kullanılan optimum parametre değerlerini belirlemek için regresyon modeli oluşturulmuştur. İlk olarak 3 farklı seviyedeki takım uç radüsü (0.4,0.6 ve 0.8 mm), talaş derinliği (0.2,0.4 ve 0.6 mm), ve ilerleme oranı (0.1,0.2 ve 0.3 mm/rev.) dikkate alınarak Box-Behnken deney tasarımı oluşturulmuştur. Ardından, elde edilen deney setlerine göre AdvantEdge™ vasıtasıyla her bir deney setine ait güç tüketimleri ölçülmüştür. Sonrasında, RSM’den elde edilen matematiksel tahmin modelinden yararlanılarak güç tüketimi tahmini için GA kullanılmıştır. Sonuç olarak, bu yöntemlerle bulunan tahmin değerleri karşılaştırılmış ve birbirlerine çok yakın oldukları görülmüştür. Hem istatistiksel hem de simülasyon programı sonuçları, güç tüketimini minimize etmek için düşük ilerleme oranı ve talaş derinliğine ihtiyaç duyulduğunu göstermektedir.Due to its widespread use in machining, reducing power consumption in the turning process is one of the key factors for a sustainable production process. Nickel-based superalloys are preferred in variable applications due to their superior mechanical properties. This study aims to investigate the effects of process parameters on power consumption in turning of Haynes 242 nickel-based superalloy. In this context, three levels of Box-Behnken design combined with the Response Surface Method (RSM) and genetic algorithm (GA) were applied to find the optimum parameter values used in the estimation of the minimum power consumption to create the regression model. First, the Box-Behnken experimental design was created based on 3 different levels of tool nose radius (0.4,0.6 and 0.8 mm), depth of cut (0.2,0.4 and 0.6 mm), and feed rate (0.1,0.2 and 0.3 mm/rev.). Then, the power consumption of each test measured by AdvantEdge™ based on the obtained experimental sets. Then, GA was used for power consumption estimation by utilizing the mathematical estimation model obtained from RSM. Finally, the estimated values obtained by both methods were compared. Both statistical and simulation results show that low feed rate and depth of cut are needed to minimize power consumption

Product Category Classification with Machine Learning

Teknolojinin ilerlemesi ve internetin gelişmesi ile beraber günümüzde bilginin gücü de ön plana çıkmıştır. Bununla beraber internet dünyasında bilgi kirliliği ve karmaşası ortaya çıkmaya başlamıştır. Bu karmaşadan anlamlı verilerin çıkartılması ve yorumlanabilmesi için makine öğrenmesi algoritmalarından yararlanılabilir. Bu çalışmada yazı formunda girilen açıklamanın kategori bilgisine ulaşılması amaçlanmıştır. Bir e-ticaret sitesinden ürün bilgileri etiketlenerek veri seti elde edilmiştir. Toplanan bu veri seti makine öğrenmesi algoritmalarıyla model eğitimi gerçekleştirilmiş ve 9 farklı katagoriye ayırmak için doğru tahminleme yapması amaçlanmıştır. Bu eğitim sırasında Random Forest, Karar Ağacı, Multinominal Naive Bayes (Multinominal NB), Logistic Regression, Destek Vektör Makineleri (DVM) ve Yapay Sinir Ağları (YSA) sınıflandırıcıları kullanılmış ve çıkan sonuçlar tablolarla karşılaştırılmıştır

Meso-piperidine linked bodipys: Synthesis, fluorescent properties and biological evaluation

The synthesis and characterization of meso-piperidine linked Bodipy starting from 4-(2-(piperidine-1-yl)ethoxy) benzaldehyde was described. Meso-piperidine linked Bodipy was subsequently used for the construction of distyryl-piperidine-Bodipy and distyryl-morpholine-Bodipy via Knoevenagel type reaction. The photophysical properties including molar extinction coefficient, fluorescence lifetime and fluorescence quantum yield of Bodipys were investigated in ethanol solution. The targeted compounds were also assessed in live cell imaging and cytotoxicity studies by using breast cancer cell line, MCF-7 in vitro

Azaindole-BODIPYs: Synthesis, fluorescent recognition of hydrogen sulfate anion and biological evaluation

The synthesized and sensing capability of two novel azaindole substituted mono and distyryl BODIPY dyes against bisulfate anion were reported. Structural characterizations of the targeted compounds were conducted by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, H-1 and C-13 NMRspectroscopies. Photophysical properties of the azaindole substituted BODIPY compounds were investigated employing absorption and fluorescence spectroscopies in acetonitrile solution. It was found that the final compounds 3 and 4 exhibited exclusively selective and sensitive turn-off sensor behavior on HSO4- anion. Additionally, the stoichiometry ratio of the targeted compounds to bisulfate anion was measured 0.5 by Job's method. Also, density function theory was performed to the optical response of the sensor for targeted compounds. Furthermore, the cytotoxicity of Azaindole-BODIPYs was examined against living human leukemia K562 cell lines

Eastern Anatolian apples with a unique population structure are genetically different from Anatolian apples

The origin of the apple is known to be the Transcaucasian region. Eastern Anatolia, which is located on the migration routes from Asia to Europe, has a rich and an uncharacterized apple germplasm and the characterization of apple genetic sources from this region is important for both evolutionary studies and apple breeding. In this study, 94 M. domestica accessions originated from seven diverse regions within Eastern Anatolia were studied using 16 SSR (simple sequence repeat) loci. SSR markers we used produced high allele numbers in all loci and CH02d11 (PI: 0.059) with 18 alleles was the most informative locus. In addition, 14 identical accession groups were identified. Most likely due to self-incompatibility, relatively high levels of heterozygosity (Ho: 0.696) was found for Eastern Anatolia apples. Structure Harvester analyses of East Anatolian apple accessions showed that although each group seems to be somewhat distinct, some levels of admixture with other populations might also exist. Due to a significant gene flow between all pairs of seven apple populations, a limited (low) differentiation was found between the populations. Comparisons using 16 common SSR loci revealed that Eastern Anatolia accessions were genetically different from Anatolian accessions. In addition, based on FCA, and Nei's genetic distance analyses, Eastern Anatolian apples were found to be genetically different from the commercial apple cultivars Golden Delicious and Florina. Our results suggesting that Eastern Anatolia apple populations have a unique structure will be useful for future genetic and evolutionary studies on apples